BACKGROUND OF THE INVENTION
[0001] The present invention relates to implants, and more particularly to an inflatable
implant including separate inner and outer lumens and an improved valve and filling
tube construction. The present invention finds particular use in implants used in
breast reconstruction and augmentation.
[0002] Breast reconstruction often is difficult after a mastectomy because of tight chest
wall skin and scarring. It is desirable to expand the skin which allows the surgeon
to avoid using skin from other parts of the body. To this end, temporary skin expanders
have been used in breast reconstruction, and these are then replaced with a suitably
sized, permanent implant. It will be appreciated that this requires two or more surgical
procedures.
[0003] There are many permanent implants on the market which are useful in breast reconstruction
and augmentation. The most commonly used is a single lumen, fixed volume implant utilizing
silicone gel. The major drawback in this implant arises from gel bleed which causes
capsular contracture. The major advantage is the natural feel which is extremely good.
[0004] In an attempt to overcome the "bleed" problem, saline filled implants have been developed.
These have greatly reduced the capsule contracture problem, but the feel is not as
good. Also, the saline filled implants are subject to spontaneous leakage caused by
wave-like motion of the saline which is transmitted to the implant membrane.
[0005] There are various "combination" implants, some using a double lumen construction
with gel in the inner chamber and saline in the outer chamber, and some with a polyurethane
sponge coating to decrease capsule contracture.
[0006] A very important goal in implants of this nature is to achieve a natural feel and
appearance and to minimize leakage and capsular contracture. Another goal is to facilitate
expansion after implantation and to permit volume adjustment.
[0007] One implant currently available is that marketed by Cox-Uphoff International termed
a Reverse Double Lumen Mammary (RDL
TM). This is a double membrane, double lumen construction having an outer membrane containing
a gel and an inner membrane which is filled with saline. The inner and outer membranes
are connected at a retention valve which allows insertion of a rigid filling tube
from outside the implant into the inner lumen. By this construction, saline can be
injected into the inner lumen at the time of implantation to fill the implant. Upon
completion of the filling process and before skin closure, the filling tube is removed.
For an explanation and understanding of the retention valve construction described
here, reference may be made to United States Patent No. 4,178,643.
[0008] The double lumen construction of the CUI implant utilizing silicone gel in the outer
lumen and saline in the inner provides a very natural and high quality appearance
and feel. However, shear forces arise in this implant at the connected area of the
membranes which increases the incidence of leakage. Also, the connected membranes
inhibit free movement of the inner and outer membranes relative to each other and
detracts from the natural feel and appearance of the implant.
[0009] In addition, the filling tube and filling valve constructions in those prior implants
which can be filled at the time of surgery are not suitable for inflation or volume
adjustment after implantation. A rigid filling tube is required and cannot be left
in place for any long period of time because of the danger of puncturing the implant
and because of discomfort to the patient caused by the rigid tube. Thus, these implants
cannot function as an expander.
[0010] It is important that the implant valves be constructed of a soft and pliable material
because the valve is a part of the implant and remains in place with the implant.
The filling tubes used with these implants often are in place in the valves for some
time (in prior devices, before implantation) so that the soft and pliable valve material
can become "set" and not recover its original shape when the tube is removed. Still
further, such prior valves and filling tubes do not always sealingly cooperate in
the desired fashion when the tube is in place. Thus, a relatively high incidence of
leakage can result in these implants acting to the detriment of these devices as permanent
implants.
SUMMARY OF THE INVENTION
[0011] The present invention provides an implant having the desirable characteristics described
above. This invention is a combination saline-gel prosthesis which provides a double
membrane, double lumen implant wherein an outer membrane forming an outer lumen contains
a viscous gel such as a silicone gel, and an inner membrane forming an inner lumen
is adapted to be filled with saline for inflation of the implant. The membranes are
totally separate from one another and the freedom of movement provided by this construction
enhances and maximizes the natural feel and appearance of the implant.
[0012] Separate valves are provided in the inner and outer membranes, respectively, and
are constructed so that a single, relatively soft and flexible filling tube connected
to a reservoir can be used to percutaneously fill the inner lumen over an extended
period of time and inflate the implant. The filling tube is sized to have an interference
fit with the valves, and means is provided to reduce the cross-sectional dimension
of the tube and to stiffen it during insertion. The valves are constructed so that
the gel in the outer lumen sealingly cooperates with both valves and with the filling
tube when the latter is in place enabling the filling tube to remain in place for
an extended period of time. Once the implant is expanded to the desired volume, the
filling tube is detached and the prosthesis remains in place as a permanent implant.
Upon removal of the filling tube, the valves are prevented from leaking by the sealing
action of the gel.
[0013] In addition to providing for tissue expansion, the implant allows for volume adjustment
postoperatively while the filling tube and reservoir are still connected. Better symmetry
of the breasts can be achieved if the implant volume can be adjusted several weeks
after surgery when swelling has decreased and the implant has settled into position.
[0014] Furthermore, the implant of this invention facilitates a method of tissue expansion
which eliminates the fear of pressure on the overlying skin and resulting necrosis
from a large implant, so that the patient is reconstructed to the most appropriate
breast size.
[0015] Additional objects and advantages of the invention will be set forth in part in the
description which follows, and in part will be obvious from the description, or may
be learned by practice of the invention. The objects and advantages of the invention
may be realized and attained by means of the instrumentalities and combinations particularly
pointed out in the appended claims.
[0016] To achieve the objects and in accordance with the purpose of the invention, as embodied
and broadly described herein, the implant of this invention comprises inner and outer
membranes, the outer membrane containing a viscous gel, first and second valves in
the inner and outer membranes, respectively, and adapted to have a singular filling
tube passed therethrough for inflating the implant, the gel in the outer membrane
sealingly cooperating with the valves and with the filling tube when the latter is
in place.
[0017] Preferably, the inner and outer membranes are separate and unattached from one another,
as are the first and second valves, and the membranes are manually manipulated to
align the valves for insertion of the singular filling tube. The inner lumen is filled
preferably with saline to inflate the implant, and the valves each comprise separable
flaps of soft, pliable material formed integral with the respective membranes and
extending inwardly thereof and surrounding openings therein. The filling tube is soft
and flexible and is insertable through the valve openings and operable to separate
the flaps when passed therebetween, and the flaps are operable to close upon removal
of the tube.
[0018] In another aspect, the invention is directed to an implant, valve and filling tube
construction comprising at least one membrane having an opening therein, the valve
including a connecting tube connected to the membrane and surrounding the opening
and extending inwardly thereof, the connecting tube having a self-sealing valve means
at the inner end thereof, a soft flexible filling tube adapted to be passed through
the opening and connecting tube and through the valve means and operable to fill the
membrane with a liquid, the filling tube having a larger cross-sectional dimension
than the connecting tube, means for applying a longitudinal stretching force to the
filling tube reducing its cross-sectional dimension to facilitate its insertion through
the connecting tube, the filling tube adapted to return to its original dimension
upon removal of the stretching force, whereby to sealingly engage the connecting tube.
[0019] Preferably, the filling tube has a longitudinal passage therethrough which is closed
at the distal end of the tube and which communicates with a transverse exit passage.
The stretching force applying means includes an elongated rod adapted to be inserted
through the passage to engage the closed end of the tube. The tube is removed from
the valve by pulling which stretches the tube and reduces its cross-section.
[0020] In a preferred form, the implant includes concentric inner and outer membranes each
having an opening and a valve, and the filling tube is adapted to be passed through
both valves to fill the inner membrane. In this form, the outer membrane contains
a gel which helps seal both valves when the filling tube is in place and when it is
removed.
[0021] The accompanying drawings, which are incorporated in and constitute a part of this
specification, illustrate one embodiment of the invention and, together with the description,
serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022]
Fig. 1 is a perspective view of an implant constructed according to the present invention
shown before inflation and with a filling tube in place;
Fig. 2 is a sectional view of the implant of Fig. 1 after inflation;
Fig. 3 is an enlarged sectional view of the implant of Figs. 1 and 2 and showing the
filling tube in position for insertion;
Fig. 4 is a view similar to Fig. 3 and showing the filling tube inserted in the implant
and longitudinally stretched;
Fig. 5 is a view similar to Fig. 4 and showing the filling tube stretching means removed
and the filling tube relaxed; and
Fig. 6 is a view similar to Fig. 5 and showing the filling tube detached from the
implant.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Reference will now be made in detail to the present preferred embodiment of the invention,
an example of which is illustrated in the accompanying drawings.
[0024] The preferred embodiment of the implant is shown in Figs. 1 and 2 and is represented
generally by the numeral 11. The implant comprises inner and outer membranes, the
outer membrane containing a viscous gel. As embodied herein, the implant 11 includes
inner and outer membranes 13, 15 which are generally concentric to one another and
form inner and outer concentric lumens 12, 14, respectively (see Fig. 2). The membranes
13, 15 are constructed of a suitable material such as a medical grade silicone rubber
which does not react with human tissue, as will be understood by those skilled in
the art. The outer membrane 15 contains an amount of viscous gel 16, for example,
a silicone rubber gel of medical grade silicone, for purposes to be described.
[0025] In accordance with the invention, first and second valves are provided in the inner
and outer membranes, respectively. The valves are adapted to have a singular filling
tube passed therethrough inflating the implant. As embodied herein and shown in Fig.
2, the inner and outer membranes 13, 15 are provided with valves 17, 19, respectively.
The valves include short connecting tubes 21, 23 which surround openings 18, 20 in
the membranes 13, 15, respectively, and are formed integral with the membranes and
extend inwardly thereof. (See also Fig. 3). A pair of opposed flaps 22, 24 extend
inwardly of and surround the tube 21 on the inner membrane 13. In substantially the
same fashion, a pair of opposed flaps 25, 27 extend inwardly of and surround the tube
23 on the outer membrane 15.
[0026] In accordance with the invention and as further embodied herein, the membranes 13,
15 are separate from and unattached to one another as are the valves 17, 19. The membranes
13, 15 are manually manipulable to align the valves 17, 19 so that a singular filling
tube can be passed through the valves for filling the inner membrane and expanding
the implant.
[0027] A filling tube 33 is shown in place extending through the valves 17, 19 in Figs.
2 and 5. The filling tube 33 is relatively soft so as not to puncture either of the
membranes, and can be inserted as shown at the time the implant 11 is manufactured.
Alternatively, a filling tube can be inserted later particularly if one becomes damaged
or if it accidentally becomes separated from the implant 11. In either case, the filling
tube 33 extends through opening 20, tube 23, and flaps 25, 27 on outer membrane 15,
and opening 18, tube 21, and flaps 22, 24 on inner membrane 13. The distal end of
tube 33 is connected to a liquid source such as a reservoir 26 and used to fill the
inner membrane with a liquid, such as saline 34 and expand the implant over an extended
period of time. Upon completion of the filling (and expansion) process, the filling
tube 33 is detached from the implant 11 and, in a manner described below, the valves
17, 19 close. For a description of an inflatable permanent implant having a detachable
filling tube and reservoir, reference may be made to applicant's copending application
Serial No. 481,912 filed April 4, 1983 which is incorporated herein in its entirety.
[0028] As described above, outer membrane 15 contains a silicone gel 16 such as a cohesive
silicone rubber gel of medical grade silicone as is used in the Reverse Double Lumen
Mammary (RDL
TM) currently marketed by Cox-Uphoff International of San- ta Barbara, California. Although
the quantity of gel in the outer lumen may vary according to the size of the implant,
approximately 40-50 cu. cm. is preferred.
[0029] The inner membrane 13 is void prior to implantation of the implant. A small amount
of saline (approximately 10% to 20% of its maximum recommended inflation amount) is
inflated after implantation to expand the implant to the desired size by delivery
of a corresponding quantity of saline 34 thereto. Saline is delivered to the inner
membrane 13 by means of the filling tube 33 which, because of its relatively soft
and flexible nature, can remain in place for a long period of time after implantation.
This allows the implant to be expanded by percutaneous injections into the reservior
over an extended period of time after surgery and provides for volume adjustment of
the implant. Once the desired size is achieved, the filling tube 33 is detached. The
entire interior contents of the expanded implant 11, i.e., the saline 34 and the gel
16, are under pressure so that flaps 22, 24 and 25, 27 are caused to close thereby
sealing the valves 17, 19.
[0030] It will be appreciated that once the filling tube 33 is removed, the membranes 13,
15 are totally free to move relative to one another so that the implant 11 is free
of any shear forces which otherwise would be present at a connection point between
the membranes. This adds to the natural feel and appearance of the implant. The gel
in the outer membrane 15 lubricates both membranes and provides the desirable characteristics
of a natural breast formation including softness and suppleness. The saline-filled
inner membrane 13 provides the necessary adjustment for the over-all size of the implant
11 and, in combination with the gel- filled outer membrane, provides the necessary
and desirable round contour of the implant.
[0031] In accordance with the invention, the gel in the outer membrane sealingly cooperates
with the valves and with the filling tube when the latter is in place. As embodied
herein and shown in Figs. 2 and 5, the connecting tubes 21, 23 are sized to snugly
receive the filling tube 33. The flaps 22, 24 and 25, 27 are formed and interconnected
with tubes 21, 23 in a manner which produces a biasing force causing flaps 22, 24
to engage and flaps 25, 27 to engage when filling tube 33 is withdrawn.
[0032] In actual practice, the filling tube 33 may remain in place in the valves 17, 19
for a long period of time, sometimes for several weeks. In that case, the flaps 22,
24 and 25, 27 may become "set" so that upon removal of the filling tube 33, the flaps
may not close fully in spite of the biasing force and the pressure assistance of the
saline and gel. In that case, the gel 16 in the outer membrane 15 fills any gap between
the flaps 25, 27 which are located in the gel containing outer lumen 14. With the
filling tube 33 removed, gel 16 can flow into the short tube 21 on the inner membrane
13 to fill any gap between flaps 22, 24. Thus, the gel 16 effects a proper seal at
both valves 15, 17.
[0033] As described above, the filling tube 33 preferably is relatively soft and flexible
to minimize the likelihood of damage to or puncturing of the membranes 13, 15 and
to prevent discomfort to the patient. The short connecting tubes 21, 23 preferably
are somewhat stiffer than the filling tube 33. Desirably, a snug fit exists between
the filling tube 33 and the connecting tubes 21, 23 and provides an effective seal
therebetween as well as to help retain the tube 33 in place. Nevertheless, some crevices
or gaps can exist between the filling tube 33 and the connecting tubes 21, 23 which
can result in leakage past the valves 15, 17 while the filling tube 33 is in place.
[0034] Furthermore, the membranes 13, 15 and the filling tube 33 stretch to an extent as
membrane 13 is filled with saline. This may cause some distortion of the connecting
tubes 21, 23 which may add to or create crevices or spaces between the filling tube
and the connecting tubes 21, 23.
[0035] In accordance with the invention and as embodied herein, gel 16 in the outer lumen
coats the filling tube 33 during insertion and seeks out and fills any crevices or
spaces between the filling tube 33 and the connecting tubes 21, 23 of valves 15, 17
when the filling tube 33 is in place. Thus, the gel 16 sealingly cooperates with the
valves 15, 17 and with the filling tube and valves when the filling tube is in place.
[0036] In accordance with the invention, means is provided to reduce the cross-sectional
dimension of the filling tube during insertion through the membrane valves, and to
allow the filling tube to expand after insertion into snug engagement with the connecting
tubes.
[0037] As embodied herein, the filling tube 33 is sized to provide an interference fit with
the connecting tubes 21, 23. The filling tube 33 has an elongated passage 37 therethrough
which is closed at the distal end of the tube and which communicates with a transverse
exit passage 39. When the filling tube is in place in the implant 11, as shown in
Fig. 5, saline from the reservoir 26 flows through passage 37 and exits passage 39
and enters the inner lumen 12.
[0038] To facilitate insertion of the soft, flexible filling tube 33 into the implant valves
15, 17, a rigid rod or wire 41 is inserted through the tube passage 37 and, by applying
force against the closed end of tube 33, causes it to stretch longitudinally. This
reduces the cross-sectional dimension of the filling tube 33, at the same time stiffening
it, so that the filling tube 33 is easily inserted through the connecting tubes 21,
23 of valves 15, 17 (see Fig. 4). When insertion is complete, the wire or rod 41 is
withdrawn and the filling tube 33 returns to its normal size and snugly engages the
connecting tubes 21, 23 (Fig. 5).
[0039] When the filling tube 33 is to be detached, a simple pulling force is applied (Fig.
6). Gel which will have coated the filling tube 33 during insertion helps removal.
Also, if the holding force of the connecting tubes 21, 23 resists removal of the filling
tube, the pulling force on the tube causes it to stretch and its cross-sectional dimension
to reduce, thereby facilitating removal.
[0040] In accordance with the invention, the implant valve and filling tube construction
described above is useful in an implant comprising at least one membrane in which
case a valve including a connecting tube is connected to the membrane and extends
inwardly thereof. The connecting tube has self-sealing valve means at its inner end.
The filling tube is constructed, inserted through, and detached from the valve as
described above.
[0041] By the foregoing, there has been disclosed an improved implant, valve and filling
tube construction calculated to fulfill the inventive objects set forth above and
inherent herein. It will be apparent to those skilled in the art that various additions,
substitutions, modifications and omissions can be made to the implant of the present
invention without departing from the scope or spirit of the invention. Thus, it is
intended that the present invention cover the additions, substitutions, modifications
and omissions provided they come within the scope of the appended claims and their
equivalents.
1. An implant and filling valve construction comprising inner and outer membranes,
said outer membrane containing a viscous gel, first and second valves in said inner
and outer membranes, respectively, and adapted to have a singular filling tube removably
passed therethrough for filling said inner membrane and inflating said implant, said
gel sealingly cooperating with said valves and with said filling tube when the latter
is in place.
2. The construction claimed in claim 1, said filling tube being soft and flexible,
whereby to allow said tube to remain in place without puncturing said implant.
3. The construction claimed in claim 1, said valves extending inwardly of the respective
membranes.
4. The construction claimed in claim 1, said inner membrane adapted to be filled with
saline.
5. The construction claimed in claim 1, said inner and outer membranes and said first
and second valves being separate and unattached to one another, whereby said membranes
are freely movable relative to one another.
6. The construction claimed in claim 1, said valves including opposed flaps extending
inwardly of the respective membranes and normally cooperatively engaging, said flaps
adapted to part upon passage of said filling tube therebetween.
7. The construction claimed in claim 5, said first valve including flexible membranes
extending inwardly of said outer lumen and normally cooperatively engaging, said flexible
members of said first valve adapted to part upon passage of said filling tube therebetween.
8. An implant, valve and filling tube construction comprising at least one membrane,
a valve including a connecting tube connected to said membrane and extending inwardly
thereof, said connecting tube having self-sealing valve means at the inner end thereof,
a soft, flexible filling tube adapted to be passed through said connecting tube and
operable for filling said membrane with a liquid, said filling tube having a larger
cross-sectional dimension than said connecting tube, means for applying a longitudinal
stretching force to said filling tube reducing its cross-sectional dimension to facilitate
its insertion through said connecting tube, said filling tube adapted to return to
its original dimension upon removal of the stretching force, whereby to sealingly
engage said connecting tube.
9. The construction claimed in claim 8, said filling tube having an elongated passage
therethrough which is closed at the distal end of said tube, said stretching force
applying means including an elongated rod adapted to be inserted through said passage
to engage the closed end of said tube.
10. The construction claimed in claim 9, said elongated passage communicated with
a transverse exit passage.
11. The construction claimed in claim 8, said implant comprising inner and outer concentric
membranes each having a valve connected thereto and extending inwardly thereof, said
outer membrane containing a viscous gel, said membranes being separate and unattached
to one another as are said valves, said filling tube adapted to pass through both
said valves for filling said inner membrane with liquid.